The incident, which occurred last Thursday, came to light after a video recorder seized from the two protesters was left recording in the back of a patrol car following the arrest of the two women near the controversial Corrib gas pipeline in Mayo.

The two protesters have declined to make their identities known and are expected to make a formal complaint against the police officers on Wednesday.

They did speak to the Irish Independent when one of the arrested pair told the paper that she and her friend were still traumatized by what they had heard on the tape.

“We were just terrified, not just as campaigners, but for others in the area. It is an incredibly serious and dangerous situation for people living in that area,” said the woman.

The pair, young environmentalists in their 20s and living in Dublin, had traveled to Mayo last week to join anti-Shell protesters at the Rossport Solidarity Camp.

Representatives of Amnesty International and the Rape Crisis Network Ireland as well as politicians have condemned the comments last night.

Colm O’Gorman, Executive director of Amnesty International Ireland, said that if the recordings were authenticated, the police must recognize their seriousness.

The Rape Crisis Network Ireland group told the Independent that: “The contents of the recording are very serious” and insisted that the public and victims of rape and sexual violence must be able to trust the police.

The Garda Síochána Ombudsman Commission announced yesterday it had launched an investigation into the matter.

Kieran FitzGerald from the Ombudsman Commission told RTE Radio: "The reported conduct of the gardaí is of such a nature as to warrant an investigation because it alleges some serious remarks and some serious conduct, which, if proven, would reflect badly on society in general and the Garda Síochána in particular."

Speaking about the investigation, Superintendent Pat Diskin of Belmullet Garda station said a senior police officer from a separate division has been appointed to “establish the facts and report on the matter”.

The Dublin Rape Crisis Centre has branded the comments as “unacceptable”.

"Making suggestive comments about rape and sexual assault is not funny whatever the situation or circumstances," chief executive Ellen O'Malley-Dunlop told the Irish Times. "Comments of this nature are totally unacceptable in any context but are much more serious when made by people in authority and who are supposed to be the guardians of our society."